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Afternoon Gents..

Just starting to build up a new TS1, noticed when checking the Threads on the Spark plug, The MAMMOTH HEAD seems slightly longer as if the Plug is short of a couple of turns if that makes sense, Had a look at the other Heads I ve got lying about and the plug just shows a thread.....Is this normal on a MAMMOTH as Im thinking it would be less if I was to put the Heat sensor ring under the spark plug.....Thanks

I think ideally the plug tip n electrode should be sitting slightly proud in the combustion bowl

TROJAN6 wrote:Afternoon Gents..

Just starting to build up a new TS1, noticed when checking the Threads on the Spark plug, The MAMMOTH HEAD seems slightly longer as if the Plug is short of a couple of turns if that makes sense, Had a look at the other Heads I ve got lying about and the plug just shows a thread.....Is this normal on a MAMMOTH as Im thinking it would be less if I was to put the Heat sensor ring under the spark plug.....Thanks

Why not bolt the sensor to the Mammoth? Have a look at Dickies winter model thread, it makes sense. I have a sensor under the plug and it rattled loose twice which is a pain, it is my plan to relocate it to the head.

Shane

shane BBoys wrote:

TROJAN6 wrote:Afternoon Gents..

Just starting to build up a new TS1, noticed when checking the Threads on the Spark plug, The MAMMOTH HEAD seems slightly longer as if the Plug is short of a couple of turns if that makes sense, Had a look at the other Heads I ve got lying about and the plug just shows a thread.....Is this normal on a MAMMOTH as Im thinking it would be less if I was to put the Heat sensor ring under the spark plug.....Thanks

Why not bolt the sensor to the Mammoth? Have a look at Dickies winter model thread, it makes sense. I have a sensor under the plug and it rattled loose twice which is a pain, it is my plan to relocate it to the head.

Shane

The mammoth head has a tapped hole at the same location as I put mine. I think it's for a k type thermocouple with 4.5mm thread.

If I can be arsed I'll be doing that to mine.

The typical 4.5mm threaded sensor that you get with a SIP clock is actually an NTC thermistor. This means that its resistance reduces with increasing temperature.
It is an unusual spec in that its resistance should read about 55K ohms at room temperature making it very difficult to spec an alternative that is more robust.
They do suffer badly from drift with age. You will notice when new, the clock reads the cold engine temp quite accurately with respect to the the surrounding ambient temperature. Over time, this reading steadily increases.
Although the clock readout goes up to 250C, I suspect the sensor is likely to be only rated to 150C. Stressing the sensor beyond this figure further aggravates the drift problem and eventually kills the sensor.
The readout then shows ---C

Improvement needed.